Moed Katan 5B

קרי עליה: ״ושם דרך אראנו בישע אלהים״.

R' Yannai read this verse about him: “And to him who orders his way, I will show the salvation of God” (Psalms 50:23), for he considered his conduct and determined when it was inappropriate to challenge his master.

תנו רבנן: אין מצינין לא על כזית מן המת, ולא על עצם כשעורה, ולא על דבר שאינו מטמא באהל. אבל מצינין על השדרה, ועל הגולגולת, על רוב בנין, ועל רוב מנין המת.

§ With regard to the halakhot of marking graves, A baraita states the following baraita: The courts do not mark the area of an olive-bulk of a corpse; nor of a bone that is the size of a barleygrain-bulk; nor of any item that imparts impurity only through physical contact but does not impart ritual impurity by means of a tent to an individual or object that it overshadows, or that is overshadowed by it, or that is found together with it under the same structure. But they do mark the area of the spine of a corpse, the skull, or the bones that comprise the majority of the skeletal structure or the majority of the number of bones in the body.

ואין מצינין על הוודאות, אבל מצינין על הספיקות. ואלו הן הספיקות: סככות ופרעות ובית הפרס. ואין מעמידין ציון במקום טומאה, שלא להפסיד את הטהרות. ואין מרחיקין ציון ממקום טומאה, שלא להפסיד את ארץ ישראל.

And furthermore, they do not mark the area of certain ritual impurity, i.e., a place that is known to all as ritually impure, but they do mark a place of uncertain ritual impurity. And these are the places of uncertain ritual impurity: Overhanging boughs, protrusions, and a beit haperas. And they do not erect the marker directly over the site of the ritual impurity, so as not to cause a loss of ritually pure food items, as one who is carrying such food might inadvertently walk up to the site of ritual impurity and only then notice the marker, after the food has already contracted impurity. Similarly, they do not distance the marker from the actual site of ritual impurity, so as not to cause a loss of Eretz Yisrael, i.e., so as not to increase the area into which individuals refrain from entering.